1. Field of the Invention
The invention relates to photocopying and more specifically to color stripping and compositing in the lithographic printing trade. An apparatus is described for reproduction art compositing, one-station film positioning, composition, multiple imaging, proofing, and plate exposure.
2. Description of the Prior Art
In the lithographic printing trade, camera negatives, positives, or color separations of a desired subject are delivered to a stripping station, usually a light table, at which time the negatives, positives, color separation negatives and screen tints are taped to various stripping bases (in some cases registered by electronic makeready equipment) as the finished product may dictate. These various stripping bases, position registered to one another and in some cases to the correct relative position to the printing plate, are known as working flats or in some cases as final plate ready flats. In either case, the flats are then transferred to a vacuum frame with an accompanying light source for exposure to another medium: film, proofing material, or the printing plate. When placing these individual flats in the vacuum frame, they are generally placed on register pins or in some cases by register marks for multiple imaging, after which vacuum closeness is applied prior to exposure to the receiving medium.
The division of tasks is generally accompanied by a physical separation of equipment and may also involve a separation of labor. Consequently, a good deal of time is spent in handling and, with complex work pieces, providing directions to those who must perform subsequent steps. Moving film from location to location or from machine to machine also offers the possibility that oral or written exposure directions will be misinterpretted, film scratched, minute dirt particles picked up, film or flat stretched or otherwise misaligned from the desired register, reducing the quality of the finished product. The physical separation of work stations demands that each negative and its base be prepared as a complete package of reasonably defined boundries, leading to the rapid consumption of stripping bases, screen tints, and like material that must be cut to fit at required locations on a stripping base.
Much of the labor, handling, material consumption, equipment, time and quality problems in the prior art are eliminated by means of the stripper's table now described.